Research Group of Prof. Dr. M. Griebel
Institute for Numerical Simulation

  author = {J. Braun and C. Burstedde and A. Kunoth},
  title = {Computing Light Masks in Neutral Atom Lithography},
  journal = {Journal of Computational Physics},
  volume = {220},
  number = {1},
  pages = {422--440},
  year = {2006},
  annote = {article,physik},
  pdf = { 1},
  abstract = {In neutral atom lithography, a collimated beam of atoms is
		  sent through a region of standing light waves created by
		  interfering laser beams. The intensity distribution of the
		  light field modulates the density distribution of the atoms
		  transversal to the beam direction. The atomic beam
		  materializes on a substrate, and the atoms are deposited in
		  a pattern which mimics the intensity distribution of the
		  light. It is thus possible to create nanostructures by a
		  suitable adjustment of the light field. While the
		  computation of the pattern of atoms generated by any given
		  setup of laser beams with known amplitudes and phases is
		  straightforward, the inverse problem of deducting the
		  appropriate amplitude and phase of each single beam to
		  create a prescribed pattern has to our knowledge not yet
		  been addressed.
		  We propose a numerical method to derive these values for a
		  fixed setup of laser beams.We consider first the general
		  case of unrelated beam directions and then specialize to
		  setups which induce periodic patterns. The solution of the
		  inverse problem is a two-step process: We use Fourier
		  techniques to compute a set of characteristic amplitude
		  values which enter the right hand side of a nonlinear
		  system of equations. This system is then solved iteratively
		  by a coordinate descent method.}